The present invention relates to an apparatus for rotating a fastening element having a polygonal section such as a hexagonal nut or bolt from an arbitrary angular position to a predetermined angular position.
When fastening elements such as nuts and bolts are to be tightened or released by an automatic tool, the polygonal section of the respective fastening element must be aligned to the actuating portion of the tool. However, when such fastening elements are delivered via e.g. a pneumatic conduit, the fastening elements will be in arbitrary angular positions. It is then necessary to rotate the fastening elements to a predetermined angular position wherein they can be engaged by the actuating portion of the tool.
It is an object of the present invention to provide an apparatus which allows to rotate a fastening element having a polygonal section from an arbitrary angular position to a predetermined angular position.
The apparatus of the present invention comprises a base member having a pocket for receiving the polygonal section of the fastening element so as to be freely rotatable therein, and a pair of positioning slides arranged in the base member on opposite sides of the pocket so as to be displaceable in parallel and opposite directions between start and end positions by actuating means. The positioning slides have positioning surfaces facing each other and extending in spaced parallel relationship. The positioning surfaces each are provided with an arcuate recess. When the positioning slides are in their start positions, opposite corners of the fastening element when in an arbitrary xe2x80x9cmis-alignedxe2x80x9d angular position project into the recesses of the positioning slides so that when the positioning slides are displaced in opposite directions, the walls of the recesses cooperate with the projecting corners of the fastening element so as to rotate the fastening element to the desired angular position wherein the positioning surfaces of the positioning slides engage opposite surfaces of the polygonal section of the fastening element.
The fastening element will then be in its predetermined angular position wherein the polygonal section of the fastening element can be engaged e.g. by an actuating portion of an automatic tool.
Preferably the positioning slides are biased by springs in a direction transverse to the direction of displacement so that they are able to perform slight lateral yielding movements opposite to the action of the springs when the positioning slides are moved from their start positions to their end positions. When the positioning slides have reached their end positions, they will be xe2x80x9cblockedxe2x80x9d so as to be prevented from performing any lateral yielding movements.